Audio Midi Setup: Change aggregate device settings

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Change aggregate device settings using Audio MIDI Setup

For your aggregate device to work correctly, all devices in the aggregate device need to have the same sample rate. The sample rate of each device should match the sample rate of the device chosen from the “Clock source” pop-up menu. If the devices in your aggregate device aren’t synchronized using hardware, such as with digital I/O connectors, you need to enable resampling to compensate for drift in the data coming from or going to devices. For more information about external clock synchronization, see the documentation that came with your audio device.

Set the sample rate

In Audio MIDI Setup, on the left side of the Audio Devices window, click the disclosure triangle next to the name of your aggregate device.

Select one of the devices that’s part of your aggregate device, and then choose the sample rate from the first Format pop-up menu on the right side of the Audio Devices window.

Repeat step 2 for all devices in the aggregate device. Make sure to choose the same setting for each device from the first Format pop-up menu.

Enable resampling

In Audio MIDI Setup, on the left side of the Audio Devices window, select the aggregate device from the list.

Choose your aggregate device settings on the right side of the Audio Devices window.

If all devices in the aggregate device aren’t synchronized via hardware, choose the device with the most reliable clock from the “Clock source” pop-up menu. Then, select the Resample checkboxes for all of the devices.

If some of the devices in the aggregate device are synchronized via hardware, choose the hardware synchronization’s clock master from the “Clock source” pop-up menu. Then, select the Resample checkboxes for all the devices that aren’t synchronized via hardware.

If all devices in the aggregate device are synchronized via hardware, choose the hardware synchronization’s clock master from the “Clock source” pop-up menu. Make sure none of the Resample checkboxes are selected.